Supplementary material: Rockseline lead chalcogenides: An alternative class of high-performance thermoelectric materials

Supplementary material provides the details of calculated lattice constants and thermal conductivities using different density functionals for lead chalcogenides in both NaCl-type structure and rockseline structure, energy profiles of phase transitions, differential charge density diagrams and simulated XRD patterns for both NaCl-type and rockseline PbTe, relaxation time and transport effective masses as a function of carrier concentration for NaCl-type and rockseline PbTe at both $n$-type and $p$-type doping, and thermoelectric performances of both NaCl-type and rockseline structures at the temperature of 300 K.